Partners Equity of The Operating Partnership (DetailsTextuals) (USD $)	6 Months Ended				12 Months Ended			0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Series C Preferred Stock [Member]	Jun. 30, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P.	Dec. 31, 2011 BRANDYWINE OPERATING PARTNERSHIP, L.P.	Jul. 19, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P.	Jul. 05, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P.	Jul. 16, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P. 7.375% Series E Preferred Shares	Jun. 30, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P. 7.375% Series E Preferred Shares	Jul. 16, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P. 6.90% Series E-linked Preferred Units [Member]	Jun. 30, 2012 BRANDYWINE OPERATING PARTNERSHIP, L.P. 6.90% Series E-linked Preferred Units [Member]	Aug. 05, 2010 BRANDYWINE OPERATING PARTNERSHIP, L.P. Class F (2010) Units
Partners Equity of The Operating Partnership (Textuals) [Abstract]
Distribution Declared per common partnership unit						$ 0.15
Dividends Payable, Amount							$ 21,600,000
Percentage of Preferential return				6.90%	0.00%				7.375%		6.90%
Dividends, Preferred Stock, Cash	5,047,000	3,996,000	200,000					1,100,000		1,800,000
Partnership units issued for acquisition												7,111,112
Market price of shares on acquisition date												11.54
Dividend rate												$ 0.60